In situ protocol for the determination of dose-response effect of low-fluoride dentifrices on enamel remineralization

No in situ protocol has assessed the dose-response effects of fluoride dentifrices involving low-fluoride formulations. objective: to assess the ability of an in situ remineralization model in determining dose-response effects of dentifrices containing low fluoride concentrations ([f]) on bovine enamel. material and methods: volunteers wore palatal appliances containing demineralized enamel blocks and brushed their teeth and devices with the dentifrices supplied (double-blind,crossover protocol) separately for 3 and 7 days. surface hardness (sh),integrated subsurface hardness (δkhn) and [f] in enamel were determined. data were analyzed by anova,tukey's test and pearson's correlation (p<0.05). results: dose-response relationships were verified between [f] in dentifrices and sh,δkhn and enamel [f]. higher correlation coefficients between enamel [f] and sh and δkhn were obtained for the 3-day period. significant differences in sh and δkhn were observed among all groups for the 3-day period,but not between 0-275,275-550,and 550-1,100 μg f/g dentifrices for the 7-day period,nor between 3- and 7-day periods for the 1,100 μg f/g groups. conclusions: considering that the peak remineralization capacity of the conventional dentifrice (1,100 μg f/g) was achieved in 3 days,this experimental period could be used in future studies assessing new dentifrice formulations,especially at low-fluoride concentrations.